On non-PREEMPT_RT kernels local_lock operations map to the preemption and
interrupt disabling and enabling primitives:
- =========================== ======================
- local_lock(&llock) preempt_disable()
- local_unlock(&llock) preempt_enable()
- local_lock_irq(&llock) local_irq_disable()
- local_unlock_irq(&llock) local_irq_enable()
- local_lock_save(&llock) local_irq_save()
- local_lock_restore(&llock) local_irq_save()
- =========================== ======================
+ =============================== ======================
+ local_lock(&llock) preempt_disable()
+ local_unlock(&llock) preempt_enable()
+ local_lock_irq(&llock) local_irq_disable()
+ local_unlock_irq(&llock) local_irq_enable()
+ local_lock_irqsave(&llock) local_irq_save()
+ local_unlock_irqrestore(&llock) local_irq_restore()
+ =============================== ======================
The named scope of local_lock has two advantages over the regular
primitives:
{
local_irq_save(flags); -> local_lock_irqsave(&local_lock_1, flags);
func3();
- local_irq_restore(flags); -> local_lock_irqrestore(&local_lock_1, flags);
+ local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock_1, flags);
}
func2()
{
local_irq_save(flags); -> local_lock_irqsave(&local_lock_2, flags);
func3();
- local_irq_restore(flags); -> local_lock_irqrestore(&local_lock_2, flags);
+ local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock_2, flags);
}
func3()
{
local_irq_save(flags); -> local_lock_irqsave(&local_lock, flags);
func3();
- local_irq_restore(flags); -> local_lock_irqrestore(&local_lock, flags);
+ local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock, flags);
}
func2()
{
local_irq_save(flags); -> local_lock_irqsave(&local_lock, flags);
func3();
- local_irq_restore(flags); -> local_lock_irqrestore(&local_lock, flags);
+ local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock, flags);
}
func3()